As will be appreciated, fluids, such as natural gas, hydrogen, process gases, refrigerants and air, have a wide array of uses in industrial and commercial applications. For instance, natural gas may be used to provide power to a range of vehicles, to heat homes during winter, and to operate various consumer appliances, such as ovens or clothes dryers. Further, natural gas may be used to generate electricity for distribution over a power grid. Different process gases and air may be used in the manufacture of an array of products and materials, including glass, steel, and plastics, for example.
To meet the demand for natural gas, companies may spend a significant amount of time and resources searching for, extracting, and transporting natural gas. Hydrogen may be produced centrally and distributed through pipelines. In process plants different gases or liquids are transported through passages to the point where it may be required. In most large factories air under pressure is made available at different points through a network of pipes. As may also be appreciated, transportation of such gases or liquids, such as through a pipeline from one point to another, is often facilitated by compression of the gas or liquid via a compressor or pump.
One common type of compressor for such applications is the reciprocating compressor. Such reciprocating compressors are positive-displacement devices that generally utilize a crankshaft that is coupled to pistons, via connecting rods and crossheads, to reciprocally drive the pistons and compress a fluid within attached compression cylinders. As may be appreciated by one skilled in the art, gas is generally introduced into compression chambers of the cylinders through one or more inlet or suction valve assemblies and, following compression, the fluid generally exits the cylinders via one or more outlet or discharge valve assemblies.
The type of valve assemblies commonly used in compressors includes poppet valves, plate valves, ring valves, channel valves and reed valves. In the current art, poppet valve, plate valve, ring valve and channel valve assemblies, all traditionally include a single or a set of sealing elements disposed between a seat plate and a guard plate. Current reed valve assemblies used in compressor applications consist of a seat plate, and a plurality of petals and guards/stoppers attached to the seat plate by a fastening means such as screws.
As many compressors routinely operate at hundreds or thousands of rotations per minute (rpm), the sealing elements also open and close at a similarly high rate. Due to this rapid cycling, the seat plate, the guard, and/or the sealing elements will often wear over time, leading to valve failure if left unchecked. To avoid such failure, in a preventive maintenance program, the valves are periodically removed from the compressor and refurbished. Sometimes failure cannot be avoided. However, the valves can typically be repaired and reused, especially the expensive seat and guard. This is typically accomplished through replacement of the sealing elements, machining/refinishing or replacement of the seat and/or guard, or the like. Of course, such maintenance is often time-consuming and/or costly.
In existing art, in the reed valve assembly, the petals and guards are attached to the seat/body/cage by individual fastening means. It is possible for these fastening means to loosen during operation, eventually coming off. Petals can fail in fatigue and pieces may break off. These loose pieces can fall into the cylinder and causing extensive damage to the compressor or engine piston/cylinder.
The cost of the power required to compress the gas is the major operational expense incurred by a company engaged in this business. The efficiency of the compressor determines the power required to operate it; the higher the efficiency, the lower the costs. Valve losses are a major source of loss in efficiency in compressors and can contribute from 5 to 20% of the overall operating costs. In existing reed valve, poppet valve, plate valve, ring valve and channel valve assemblies used in the compression process, the gas has to make two right angle turns to get by the sealing element while passing through the valve. The greater the turning angle, the greater the resistance to the flow through the compressor; directly affecting the efficiency adversely.
The amount of time required to install a valve successfully, determines the amount of time that a machine is down and, in turn, the amount of money that is lost due the machine being down. For valves installed in the field, it is very difficult to check the quality of the assembled valve as this depends on the tolerance of all the parts and how it is assembled. A minor problem in a seat or guard can mean that none of the sealing elements seal properly—and this can only be found after the entire valve has been assembled and installed.